Multi-residue methods for the determination of over four hundred pesticides in solid and liquid high sucrose content matrices by tandem mass spectrometry coupled with gas and liquid chromatograph

Ratiometric fluoroprobe based on Eu-MOF@Tb3+ for detecting tetracycline hydrochloride in freshwater fish and its application in rapid visual detection

Tetracycline hydrochloride (TCH), a prevalent antibiotic in aquaculture for treating bacterial infections, poses challenges for on-site detection. This study employed the reversed-phase microemulsion method to synthesize a uniform nano metal-organic framework (MOF) material, europium-benzene-p-dicarboxylic acid (Eu-BDC), doped with Tb3+ to form a dual-emission fluorescence probe. By leveraging the combined a-photoinduced electron-transfer (a-PET) and inner filter effect (IFE) mechanisms, high-sensitivity TCH detection in Carassius auratus and Ruditapes philippinarum was achieved. The detection range for TCH is 0.380-75 μM, with a low limit of detection (LOD) at 0.115 μM. Upon TCH binding, Eu-BDC fluorescence rapidly decreased, while Tb3+ fluorescence remained constant, establishing a ratiometric fluorescence change. Investigation into the TCH quenching mechanism on Eu-BDC was conducted using time-dependent density functional theory (TD-DFT) calculations and fluorescence quenching kinetic equations, suggesting a mixed quenching mechanism. Furthermore, a novel photoelectric conversion fluorescence detection device (FL-2) was developed and evaluated in conjunction with high-performance liquid chromatography-diode-array detection (HPLC-DAD). This is the first dedicated fluorescence device for TCH detection, showcasing superior photoelectric conversion performance and stability that reduces experimental errors associated with smartphone photography methods, presenting a promising avenue for on-site rapid TCH detection.

Pesticide screening of surface water and soil along the Mekong River in Cambodia

Widespread use of pesticides globally has led to serious concerns about environmental contamination, particularly with regard to aquatic and soil ecosystems. This work involved investigating concentrations of 64 pesticides in surface-water and soil samples collected in four provinces along the Mekong River in Cambodia during the dry and rainy seasons (276 samples in total), and conducting semi-structured interviews with local farmers about pesticide use. Furthermore, an ecological risk assessment of the detected pesticides was performed. In total, 56 pesticides were detected in surface water and 43 in soil, with individual pesticides reaching maximum concentrations of 1300 ng/L in the surface-water samples (tebufenozide) and 1100 ng/g dry weight in the soil samples (bromophos-ethyl). The semi-structured interviews made it quite evident that the instructions that farmers are provided regarding the use of pesticides are rudimentary, and that overuse is common. The perceived effect of pesticides was seen as an end-point, and there was a limited process of optimally matching pesticides to pests and crops. Several pesticides were used regularly on the same crop, and the period between application and harvest varied. Risk analysis showed that bromophos-ethyl, dichlorvos, and iprobenfos presented a very high risk to aquatic organisms in both the dry and rainy seasons, with risk quotient values of 850 for both seasons, and of 67 in the dry season and 78 in the rainy season for bromophos-ethyl, and 49 in the dry season and 16 in the rainy season for dichlorvos. Overall, this work highlights the occurrence of pesticide residues in surface water and soil along the Mekong River in Cambodia, and emphasizes the urgent need for monitoring and improving pesticide practices and regulations in the region.

Stereoselective analysis of chiral pesticides: a review

Chiral organic pollutants, including pesticides, herbicides, medicines, flame retardants, and polycyclic musk, represent a significant threat to both the environment and human health. The presence of asymmetric centers in the structure of chiral pesticides introduces stereoisomers with distinct distributions, fates, biomagnification capacities, and cytotoxicities. In aquatic environments, pesticides, as persistent/pseudo-persistent compounds, have been detected in substantial quantities, posing severe risks to non-target species and, ultimately, public health through water supply and food exposures. In response to this environmental challenge, stereoselective analytical methods have gained prominence for the identification of pesticide/drug enantiomers in recent years. This review examines the environmental impact of chiral pesticides, emphasizing the distinct biological activities and distribution patterns of their stereoisomers. By highlighting the advancements in liquid chromatography for enantiomeric analysis, the review aims to underscore the urgent need for a comprehensive understanding of these pollutants to facilitate informed remediation strategies and ensure the safer dispersal of chiral organic pollutants in the environment, thereby addressing the potential risks they pose to ecosystems and human health. Future research should focus on developing sustainable and efficient methodologies for the precise analysis of stereoisomers in complex matrices, particularly in sewage water, emphasizing the importance of sewage processing plants in ensuring water quality.

Pesticide Residues in Mandarins: Three-Year Monitoring Results

The demand of plant production product use has increased because of the current system of citrus production, which prioritizes high agricultural yields. Therefore, the monitoring of pesticide residues in citrus fruits and other agricultural products and their impacts on human health and food security are of great concern. This study aims to determine multi-class pesticides including highly polar residues in satsuma mandarins. A total of 226 mandarin samples were collected over three consecutive harvesting years from 2019 to 2021 in the Izmir region of Turkey. Targeted compounds included pesticides and metabolites with European Union (EU) regulatory levels, plus other non-approved residues and highly polar compounds. The residues excluding highly polar substances were analyzed by applying the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) determination for 434 analytes and gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) determination for 71 analytes. For six highly polar pesticides, sample preparation was based on Quick Polar Pesticides (QuPPe) extraction. The polar residues were determined by LC-MS/MS using internal standards. Forty different residues, including two highly polar substances, were recorded in mandarin samples through three harvesting years. In 8.4% of the samples, no quantifiable residues were detected, whereas 207 samples contained at least one residue. The maximum residue level (MRL) exceedances were recorded for 22.1% of the samples. The two most frequently found pesticides were phosphonic acid and spirotetramat, with an incidence rate of 48.7% and 46.5%, respectively. The concentration of phosphonic acid and spirotetramat in mandarin samples varied from 0.026 to 39.386 mg kg^-1 and from 0.010 to 1.485 mg kg^-1, respectively. The results will enable researchers and regulatory authorities to assess the extent of pesticide presence, identify potential risks, and take necessary measures to ensure the safety of satsuma mandarins for consumers.

Quantification of 363 Pesticides in Leafy Vegetables (Dill, Rocket and Parsley) in the Turkey Market by Using QuEChERS with LC-MS/MS and GC-MS/MS

Contamination of agricultural products with pesticide residues is a growing concern due to their adverse health effects and increasing worldwide usage of pesticides. In 2021 a total of 200 samples of green leafy vegetables, including 80 dill, 80 rocket and 40 parsley, purchased from greengrocer shops, markets and bazaars in Corum Province, Turkey, were monitored for pesticide residues. In green leafy vegetables, 363 pesticides were analyzed using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation, followed by liquid chromatography coupled to mass spectrometry (LC-MS/MS) for 311 residues and gas chromatography coupled to mass spectrometry (GC-MS/MS) for 52 residues. The method was in-house validated at two fortification levels, and satisfactory recoveries and precisions were achieved for all residues. No quantifiable residues were found in 35% of the samples, whereas 43 residues belonging to 24 different chemical classes were detected in 130 green leafy vegetables. Among the green leafy vegetables, the highest occurrence frequency was recorded in the rocket, followed by dill and parsley. In 46% of the green leafy vegetables, the residue levels exceeded European Union Maximum Residue Levels (EU MRLs). The most frequently detected pesticides were pendimethalin (22.5%), diuron (38.7%) and pymetrozine (52.5%) in dill, rocket and parsley, respectively.

Method Validation for Multi-Pesticide Residue Determination in Chrysanthemum

The chrysanthemum can be consumed in various forms, representing the "integration of medicine and food". Quantitative analysis of multi-pesticide residues in chrysanthemum matrices is therefore crucial for both product-safety assurance and consumer-risk evaluation. In the present study, a simple and effective method was developed for simultaneously detecting 15 pesticides frequently used in chrysanthemum cultivation in three matrices, including fresh flowers, dry chrysanthemum tea, and infusions. The calibration curves for the pesticides were linear in the 0.01-1 mg kg^-1 range, with correlation coefficients greater than 0.99. The limits of quantification (LOQs) for fresh flowers, dry chrysanthemum tea, and infusions were 0.01-0.05 mg kg^-1, 0.05 mg kg^-1, and 0.001-0.005 mg L^-1, respectively. In all selected matrices, satisfactory accuracy and precision were achieved, with recoveries ranging from 75.7 to 118.2% and relative standard deviations (RSDs) less than 20%. The validated method was then used to routinely monitor pesticide residues in 50 commercial chrysanthemum-tea samples. As a result, 56% of samples were detected with 5-13 pesticides. This research presents a method for the efficient analysis of multi-pesticide residues in chrysanthemum matrices.

Integrated QuEChERS strategy for high-throughput multi-pesticide residues analysis of vegetables

An integrated QuEChERS strategy was developed by combining the extraction and purification processes into a single step. All of the pretreatment procedures could be performed in one tube within 5 min with the aid of magnetic nanoparticles and careful optimization of the key parameters, including the dosages of the sorbents (magnetic nanoparticles, C18, and graphitized carbon black), dehydrating and salting out reagents. The optimal method was validated and compared with the conventional QuEChERS method, demonstrating its clear superiority in terms of operating procedure, sample pretreatment time, and reagent dosages while affording equivalent pesticide recoveries and matrix effects. Further application of this method was performed to analyze 127 pesticide residues in solanaceous vegetables (tomato, pepper, and eggplant), leafy vegetables (brassica campestris and cabbage), legumes (green beans and cowpea), melon-type vegetables (cucumber and towel gourd), and a root vegetable (water bamboo), with the mean recoveries of the pesticides in the individual vegetable samples ranging from 70.6 to 92.8%. The method LOQs for these pesticides ranged from 10 to 50 μg/kg depending on the matrix. These results fully confirmed its wide applicability and versatility for achieving robust, rapid, and high-throughput multi-pesticide residues analysis in vegetable samples. More importantly, the developed strategy provides a greener and more "QuEChERS" design concept, which could be applied to the analysis of numerous types of pesticide residues in various matrices.

Determination of five pesticides in kumquat: Dissipation behaviors, residues and their health risk assessment under field conditions

The present study was carried out to profile the dissipation patterns and residues of five pesticides (triazophos, profenofos, chlorpyrifos, etoxazole and bifenthrin) on kumquat using QuEChERS method coupled with HPLC-MS/MS. The corresponding dietary health risks were also estimated. In the method validation, satisfactory results of good linearity (r2 ≥ 0.9956), sensitivity (limits of quantification ≤0.01 mg/kg), recoveries (71.0-95.7%) with relative standard deviations (0.70-9.4%) were obtained. The half-lives of the five pesticides in kumquat were 13.6-38.5 d under field conditions according to first-order kinetics. Based on the final residue experiment, dietary exposure risks of profenofos, chlorpyrifos, etoxazole and bifenthrin were all acceptably low, with RQc and RQa values of 0.00199-0.122 and 0.00145-0.200, respectively. However, exposure intake of triazophos posed unacceptable acute and chronic health risks for Chinese residents, especially for children with RQa and RQc up to 4.25 and 2.19. Forbidden use suggestion of triazophos and recommended MRLs of profenofos and bifenthrin were put forward in kumquat for safe production and consumption. This work was significant in providing guidance on appropriate application and MRL establishment of pesticides in kumquat.

Onsite/on-field analysis of pesticide and veterinary drug residues by a state-of-art technology: A review

Pesticides and veterinary drugs are generally employed to control pests and insects in crop and livestock farming. However, remaining residues are considered potentially hazardous to human health and the environment. Therefore, regular monitoring is required for assessing and legislation of pesticides and veterinary drugs. Various approaches to determining residues in various agricultural and animal food products have been reported. Most analytical methods involve sample extraction, purification (cleanup), and detection. Traditional sample preparation is time-consuming labor-intensive, expensive, and requires a large amount of toxic organic solvent, along with high probability for the decomposition of a compound before the analysis. Thus, modern sample preparation techniques, such as the quick, easy, cheap, effective, rugged, and safe method, have been widely accepted in the scientific community for its versatile application; however, it still requires a laboratory setup for the extraction and purification processes, which also involves the utilization of a toxic solvent. Therefore, it is crucial to elucidate recent technologies that are simple, portable, green, quick, and cost-effective for onsite and infield residue detections. Several technologies, such as surface-enhanced Raman spectroscopy, quantum dots, biosensing, and miniaturized gas chromatography, are now available. Further, several onsite techniques, such as ion mobility-mass spectrometry, are now being upgraded; some of them, although unable to analyze field sample directly, can analyze a large number of compounds within very short time (such as time-of-flight and Orbitrap mass spectrometry). Thus, to stay updated with scientific advances and analyze organic contaminants effectively and safely, it is necessary to study all of the state-of-art technology.

Rapid Screening and Quantification of Multi-Class Multi-Residue Veterinary Drugs in Pork by a Modified Quechers Protocol Coupled to UPLC-QOrbitrap HRMS

Background:

A rapid and simple analytical method for the screening and quantification of multi-residues was established by a quick, easy, cheap, effective, rugged and safe (QuEChERS) approach coupled to ultra-performance liquid chromatography and electrospray ionization quadrupole orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap HRMS). A total number of 59 veterinary drugs were investigated, which belonged to 12 classes, such as β-agonist, quinolones, sulfonamides, tetracyclines, lincomycin series, triphenylmethane, nitroimidazoles, macrolides, amide alcohols, quinoxalines, steroid hormone and sedatives.

Methods:

The factors which influence the determination of veterinary drugs residues, such as mobile phase, extract solvent, clean up sorbent, and re-dissolved solvent, were optimized by the single factor experiment. The method was sufficiently validated by using the parameters of linearity, sensitivity, accuracy, and repeatability.

Results:

The response of the detector was linear for 59 veterinary drug residues in extensive range (two to three orders of magnitude) with a high coefficient of determination (R2) (0.9995-0.9998). The limit of quantification (LOQ) ranged from 0.1μg/kg to 2.0μg/kg for 59 veterinary drug residues in pork samples. The repeatability was in the range of 1.0%-9.5%. Average recoveries of 59 veterinary drugs at three spiked levels ranged from 53.7%-117.8% with relative standard deviation (RSD) of 1.9%-13.9%. The full MS scan coupled with data-dependent MS/MS mode was applied for screening the target compounds to simultaneously obtain the accurate mass of parent ion and the mass spectrum of fragments. Elemental composition, accurate mass, and retention time and characteristic fragment ions were used to establish a homemade database.

Conclusion:

The ability of the homemade database was verified by analyzing the real pork samples, and the result was satisfactory.

Synergistic effect of Ficus-zero valent iron supported on adsorbents and Plantago major for chlorpyrifos phytoremediation from water

Chlorpyrifos and the metabolite 3, 5, 6-trichloro-2-pyridinol (TCP) are widespread contamination of aquatic environments especially freshwater fish. The objectives of this study were to evaluate the contribution of using Ficus zero-valent iron nanoparticles supported on adsorbents (F-Fe⁰ ad) as green nanotechnology and Plantago major as phytoremediation for removing chlorpyrifos and degradation product TCP polluted water. The shapes of F-Fe⁰ were circular, with sizes from 2.46 nm to 11.49 nm. Wheat bran (WB) showed the highest extent of removal of chlorpyrifos, while Rice straw ash (RSA) showed the lowest extent of removal. F-Fe⁰ supported on adsorbents has demonstrated faster removal toward chlorpyrifos compared with tested adsorbents or F-Fe⁰. Chlorpyrifos was removed more quickly and effectively by P. major L. plus F-Fe⁰ supported on different adsorbents (nearly 100%) than that by P. major (43.76%) or F-Fe⁰ (81.69%). The degradation product TCP was more greatly accumulated in water treated with F-Fe⁰ than that P. major alone or F-Fe⁰ supported with adsorbents and combined with P. major. Furthermore, TCP significantly accumulated in P. major roots and leaves in the water treated with F-Fe⁰ supported with adsorbents plus P. major more than that in the P. major roots and leaves alone, this is attributed to the role of F-Fe⁰ adsorbents for the degradation of chlorpyrifos to TCP, Which strongly accumulated in the P. major roots and leaves. It can be concluded that the contribution of using F-Fe⁰ supported on adsorbents, especially WB as green nanotechnology and P. major as phytoremediation would be a major role for the complete removal of chlorpyrifos from the water with a significant reduction in the toxic degradation product TCP.

Removal of epoxiconazole and pyraclostrobin from highly contaminated effluent (grams per liter level): Comparison between ozone and solar still decontamination using real field conditions

Brazilian environmental legislation obliges the aeroagriculture operators to treat the effluents generated after aircraft washing. This effluent commonly contains high levels of pesticides (g L^-1) with potential to produce point source pollution. In the present study, we evaluated the efficiency of two systems on the removal of the fungicides epoxiconazole and pyraclostrobin from these effluents. The first system is based on ozonation and is currently suggested by regulatory authority. The second system is based on a pyramid-shaped solar still. The pesticides removal was monitored using liquid chromatography mass spectrometry to determine the mass quantity of both molecules throughout the treatment. After treatment with ozone treatment, the total mass of epoxiconazole decreased by 73% and pyraclostrobin decreased by 90.8%. The solar distillation system removed epoxiconazole and pyraclostrobin by >99.995 and 99.99%, respectively. The both systems proved to be efficient in the treatment of effluent containing residues of the fungicide Opera®, a formulation containing epoxiconazole and pyraclostrobin. The solar distillation system showed a higher degree of removal and presents the advantage of operating without energy sources, reagents or consumables.

Analysis of pesticide residues in commercially available chenpi using a modified QuEChERS method and GC-MS/MS determination

To ensure the safety of the commercially available chenpi, a convenient and fast analytical method was developed for the determination of 133 pesticide residues in chenpi using gas chromatography-tandem mass spectrometry (GC-MS/MS). In this study, different extraction solvents, redissolution solvents and adsorbents were tested according to the recovery and purification effect to obtain a modified QuEChERS method. The samples were extracted with acetonitrile. During the clean-up step, octadecyl-modified silica (C18) and graphitized carbon black (GCB) were selected, and aminopropyl (NH₂) was used instead of primary secondary amine (PSA) because of its weaker ion exchange capacity which had little effect on the recovery of ditalimfos. Samples were quantified by matrix-matched calibration with internal standards. All pesticides showed good linearity in the respective range, both with values of r² > 0.99. The average recoveries of the pesticides spiked samples ranged from 70.0% to 112.2% with the RSDs of 0.2%–14.4%. The modified QuEChERS method was validated and applied to twenty real samples. Five pesticides were found in eight batches, but no pesticide exceeded the maximum residue limits (MRL, MRL reference to European commission).

Multiresidue analytical method for the determination of 41 multiclass organic pollutants in mussel and fish tissues and biofluids by liquid chromatography coupled to tandem mass spectrometry

In this work, the full optimisation and validation procedure to analyse a wide set of emerging organic contaminants in biotissues (mussel and fish muscle, liver, gills and brain) and biofluids (fish plasma and bile) is described. The target families include artificial sweeteners, industrial products, hormones, pharmaceutical and personal care products, pesticides and phytoestrogens. Different clean-up strategies (hydrophilic-lipophilic-balanced (HLB) solid-phase extraction, Florisil solid-phase extraction and liquid-liquid extraction followed by HLB solid-phase extraction and microextraction based on polyethersulfone polymer) were evaluated for the clean-up of focused ultrasonic solid-liquid extraction (FUSLE) extracts before the analysis by liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). The methods afforded satisfactory apparent recovery values (71-126%) using isotopically labelled analytes and matrix-matched calibration approach, regardless of the matrix. Method detection limits in the range of 4-48 ng/g and 0.3-111 ng/L were obtained for biotissues and biofluids, respectively. The developed method was applied to determine the uptake and tissue distribution in juvenile gilt-head bream (Sparus aurata) during 7 days in seawater, and unexpectedly, perfluoro-1-butanesulfonate tended to accumulate in liver and, to a lesser extent, in muscle and gills. Furthermore, real mussel samples collected in the Basque coast were also analysed and the presence of the highly consumed valsartan (7 ng/g) and telmisartan (6.8 ng/g) compounds in bivalves is reported for the first time here. Graphical abstract ᅟ.

Do chlorinated insecticides (aldrin and DDT) or products of their transformations (dieldrin and DDE) impair signal transfer from regulators (oxytocin and relaxin) of bovine myometrium motility in vitro?

Aldrin, dieldrin, and DDT are chlorinated insecticides that are unintentionally widespread in the environment. It was previously shown that all of the aforementioned compounds increased secretion of ovarian oxytocin (OT), which is a potent uterotonic agent. However, only DDT and its metabolite (DDE) promoted, while aldrin and dieldrin inhibited basal and OT-stimulated myometrial contractions in cows. Therefore, the aim of this study was to determine the effect of these treatments on the reception and further transmission of the OT-signal for myometrial contractions and on the levels of contractile-associated integral proteins (caveolin; CAV) and gap junction proteins (GAPs). Moreover, their effect on reception of signal for the relaxation of myometrium was also studied. Myometrial strips or cells from non-pregnant (8-12 days of oestrous cycle) or late pregnant (5-8 months) cows were incubated with the studied compounds at environmentally relevant dose (10 ng/ml), which was chosen according to the previous studies. DDT and DDE increased the CAV protein level, while dieldrin decreased the GAPs level. None of the studied compounds affected mRNA expression of the OT receptor and expression of the second messengers (DAG, IP3, PKC, MLCK). Oppositely, DDE and dieldrin decreased mRNA expression of the relaxin (RLX) receptor. Changes in the amount of contractile-associated integral proteins may be involved in the molecular mechanism underlying the adverse effects of the studied insecticides on myometrial motility. Admittedly, none of the studied compounds impaired the reception or further intracellular transmission of the OT signal to promote contractions during the oestrous cycle, while they showed potential to impair the transmission the signal between cells as well as to diminish the effects of one of the primary inhibitor (RLX) of myometrial contractions during gestation.

An efficient cleanup method coupled with gas chromatography and mass spectrometry for multi-pesticides residue analysis in complex plant matrices

We aimed to develop an efficient cleanup method for multi-pesticides residue analysis in complex plant matrices, shallot, ginger, garlic, onion, leek, and celery. Column chromatography was used as the cleanup method and fabricated with florisil and graphitized carbon black as the adsorbents. The amount of the graphitized carbon black adsorbent and the choice of the elution solvent were systematically investigated for exploring the best combination. The target pesticides covered organochlorine, pyrethroid, and organophosphorus pesticides, and were 38 in total. The method validation and comparison were performed to verify its feasibility and advantages in operation convenience and purification efficiency. The method limit of quantitation varied from 0.01 to 0.03 mg/kg, which depends on the pesticides and the sample matrices. The recoveries of the pesticides ranged from 60.5 to 128% (RSD ≤ 19.0%) at the spiked concentration level of 0.01 (or 0.03) mg/kg and 62.9 to 130% (RSD ≤ 13.0%) at 0.1 mg/kg. Compared with the commercial cleanup solid-phase extraction cartridges, the present adsorbent combination displayed better purification effect and shorter sample pretreatment time, demonstrating potential application prospect in the complex matrix sample analysis.

Glyphosate affects the secretion of regulators of uterine contractions in cows while it does not directly impair the motoric function of myometrium in vitro

The effects of pure glyphosate and its most popular product (brand name: Roundup) on the secretion of hormones involved in the regulation of myometrial contractions as well as their direct effects on myometrial contractions were examined. Myometrial strips as well as uterine and ovarian cells were taken from cows during the oestrous cycle and they were treated with both compounds at concentrations from their environmental range. Glyphosate stimulated the secretion of oestradiol from granulosa cells while both herbicides increased and decreased oxytocin (OT) and progesterone secretion from luteal cells respectively. However only Roundup stimulated mRNA expression of the precursor of OT. Both compounds decreased the secretion of prostaglandins from endometrial cells while they exerted no effect on the basal and OT-stimulated force of myometrial contractions. The studied herbicides did not directly impair the motoric function of the myometrium. However our data indicate the potential of these compounds to disturb the secretory functions of the ovaries and uterus which can lead to the deregulation of uterine contractions and to the impairment of fertilisation or to difficulties in the maintenance of gestation.

Chlorinated insecticides (toxaphene and endrin) affect oxytocin, testosterone, oestradiol and prostaglandin secretion from ovarian and uterine cells as well as myometrial contractions in cow in vitro

We examined the direct effects of toxaphene and endrin, chlorinated insecticides that are widespread in the environment, on myometrial contractions and on the secretion of hormones involved in regulating these contractions. Granulosa, luteal, endometrial and myometrial cells, and myometrial strips from non-pregnant cows were incubated with both insecticides at environmentally relevant doses. Toxaphene inhibited and endrin stimulated the secretion of testosterone and oestradiol from granulosa cells. Toxaphene also inhibited and endrin stimulated the expression of the mRNA encoding the precursor of oxytocin (OT), as well OT secretion in luteal cell cultures. Moreover, endrin increased OT secretion from granulosa cells. Neither insecticide exerted an effect on progesterone secretion from luteal cells. Only toxaphene decreased the secretion of prostaglandins (PGF2 and PGE2) from endometrial cells. Meanwhile, only endrin decreased basal myometrial contractions, which was accompanied by inhibition of PGF2 secretion from the myometrium. Both endrin and toxaphene also decreased the force of the OT-stimulated myometrial contractions, whereas only toxaphene inhibited the stimulatory effect of OT on the force of myometrial contractions. In contrast to endrin, toxaphene decreased synthesis and secretion of one of the primary stimulators of myometrial contractions (OT) and indirectly inhibited OT signal reception in the myometrium by reducing E2 secretion. Both insecticides decreased OT-stimulated myometrial contractions; therefore, they may inhibit further transmission of the OT signal. Moreover, endrin inhibited basal myometrial contractions, potentially resulting from reduced PGF2 secretion from the myometrium. Our data indicate the potential of these insecticides to disturb the course of the oestrous cycle or fertilisation.

Pesticide Residues in Table Grapes and Exposure Assessment

This report describes levels of 172 pesticide residues in table grapes in Turkey. A total of 280 samples of table grapes were collected from supermarkets, bazaar, and greengrocer shops located in four provinces of Turkey from August to October 2016. The samples were analyzed by liquid chromatography coupled to tandem mass spectrometry. The limit of quantification ranged from 0.002 to 0.010 mg kg^-1. The validation data revealed good recoveries and good repeatability and reproducibility and fulfilled the other requirements of the European SANTE/11945/2015 Guideline. One or more pesticide residues were detected in 59.6% of the table grapes. The residues above the EU maximum residue levels were 20.4% of the samples. The most prevalent pesticide residues were azoxystrobin, chlorpyrifos, boscalid, and cyprodinil. Left-censored results (40.4% of the results) were substituted by lower bound , middle bound, and upper bound values. In the worst-case scenario, the hazard index (HI) was 3.37% for adults and 9.42% for children. Chlorpyrifos was the major contributor (65%) to HI.

Multiresidue Method for the Rapid Determination of Pesticide Residues in Tea Using Ultra Performance Liquid Chromatography Orbitrap High Resolution Mass Spectrometry and In-Syringe Dispersive Solid Phase Extraction

A method based on in-syringe dispersive solid phase extraction (IS-D-SPE) and ultra performance liquid chromatography Orbitrap high resolution mass spectrometry for the multiresidue analysis of 117 pesticides in tea was developed. Full scan mode was acquired over an m/z range of 100-800 with Orbitrap resolution at 70000, followed by full scan/dd-MS² mode for confirmation. The identification criteria of retention time and mass accuracy tolerance was ±0.20 min and ±5.0 ppm, respectively. MS/MS fragment ions obtained dd-MS² were necessary to identify the pesticides with the same molecular mass weight. The IS-D-SPE technique involved a mixture of 200 mg PSA, 100 mg C18, and 15 mg multiwalled carbon nanotubes for the cleanup of tea matrix. Good linearity (R² > 0.99) for 117 pesticides was obtained. Satisfactory recoveries in the range of 70-120% were obtained for 105 pesticides, while intraday and interday precisions were below 20%. Limits of quantification were generally 10 μg kg^-1. Finally, this method was employed to analyze 117 pesticides in 70 tea samples.

Evolution of novel sorbents for effective clean-up of honeybee matrix in highly toxic insecticide LC/MS/MS analysis

Highly toxic insecticides (HTIs) belonging to different chemical groups are dangerous to pollinating organisms, even in sublethal doses. An important objective of this study was to develop a method to determine over fifty HTIs at very low concentrations in the bee matrix. The novelty of this research involved obtaining extract completely free from beewaxes, lipids and proteins using EMR-lipid (enhanced matrix removal-lipid), chitin and Z-Sep+ (zirconium oxide and C18 dual-bonded to silica) as clean-up sorbents. Different parameters, such as weight of bees, extraction solvent, and freezing time were evaluated. Determinations were made using liquid chromatography-tandem mass spectrometry (LC-MS/MS). EMR-lipid allows for removing most of the fatty co-extracts and increases the overall performance of the method by reducing the matrix effects (ME) without significant analyte loss. The established modified QuEChERS method based on 1% acetic acid in acetonitrile extraction followed by EMR-lipid clean-up was validated at three different spiking levels (0.001, 0.01 and 0.1mgkg^-1). Precision, calculated as relative standard deviation (RSD), was below 20%. The proposed method was used to determine sublethal doses of these insecticides in real samples of dead honeybees.

Multiclass pesticide residue analysis in fish muscle and liver on one-step extraction-cleanup strategy coupled with liquid chromatography tandem mass spectrometry

The analysis of pesticide residues in fish samples is challenging due to the low concentrations and large number of analytes that need to be monitored and quantified in a complex matrix. This is the first report providing a novel one-step extraction-cleanup strategy for simultaneous analysis of over 340 pesticides in a fatty fish and liver matrix, coupled with liquid-chromatography tandem mass spectrometry. The samples of fish muscle and liver were prepared according to the modified QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure, wherein the extraction and cleanup protocol were integrated into one step. Among the tested cleanup dispersive solid phase extraction sorbents (C18, primary-secondary amine, Z-Sep), chitin yielded the best results. Spike-in experiments were carried out at three different spiking levels in fish and liver to determine the recovery, precision and limits of detection of the method as well as the matrix effect. The method's detection limits ranged from 0.05 to 1.2μgkg^-1, while recoveries of most pesticides were in the range of 70-120% with associated precision - relative standard deviations below 20%. A linear relationship was observed within the range of 0.005-1mgkg^-1, and the correlation coefficient was R²>0.997. Expanded measurement uncertainty was estimated to be between 7% and 52%, on average. Matrix effects were evaluated and were not significant for the vast majority of pesticides. The validated method was employed in the analysis of 54 real fish and liver samples in which 10 different pesticides with concentrations ranging from 0.005 to 0.047mgkg^-1 were detected.

Influence of QuEChERS modifications on recovery and matrix effect during the multi-residue pesticide analysis in soil by GC/MS/MS and GC/ECD/NPD

A QuEChERS extraction followed by GC/MS/MS and GC-μECD/NPD for 216 pesticide and metabolites determination in soil simultaneously were developed and compared. Volume of water, volume and polarity of solvent, and cleanup sorbents (C18, GCB, PSA) were optimized. The QuEChERS with and without purification step were applied to estimate effectiveness of the method. The recovery and matrix effect (ME) were critical parameters within each tested procedure. The optimal method without cleanup was validated. Accuracy (expressed as recovery), precision (expressed as RSD), linearity, LOQ, and uncertainty were determined. The recoveries at the three spiking levels using matrix-matched standards ranged between 65 and 116% with RSD ≤17 and 60-112% with RSD ≤18% for MS/MS and μEC/NP, respectively. The LOQ ranged from 0.005-0.01 mg/kg for MS/MS to 0.05 mg/kg for μEC/NP. The ME for most of pesticides resulted in enhancement of the signal and depended on the analyte and detection system: MS/MS showed ME from -25 to 74%, while μEC/NP from -45 to 96%. A principal component analysis was performed to explain the relationships between physicochemical parameters and ME of 216 pesticides. The QuEChERS protocol without the cleanup step is a promising option to make the method less expensive and faster. This methodology was applied in routine analysis of 263 soil samples in which p,p' DDT was the most frequently detected (23.5% of samples) and pendimethalin with the highest concentration (1.63 mg/kg).